code: def on_draw(self, event):
      self.context.clear(color=True, depth=True)
      self.program.draw("triangle_strip")
  
file_path: vispy/examples/gloo/spatial_filters.py
imports: import numpy
  from vispy.io import load_spatial_filters
  from vispy import gloo
  from vispy import app
  from vispy.util.logs import set_log_level
label_desc: Use image node_id 4 for calling the Canvas obj's underlying member method code with example usage: obj.on_draw(event) without return types